Add ScopedMacRTL class for Cocoa browser RTL testing

chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm

Index: chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm
diff --git a/chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm b/chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm
index 3d8710d44f4dccf8ba35afb1b2f9afd019ff0189..a1f3df4611ff1325f60390eb177c4f41fe52f96d 100644
--- a/chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm
+++ b/chrome/browser/ui/cocoa/profiles/avatar_base_controller.mm
@@ -19,7 +19,7 @@
 #include "chrome/browser/ui/browser_window.h"
 #import "chrome/browser/ui/cocoa/base_bubble_controller.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
-#include "chrome/browser/ui/cocoa/l10n_util.h"
+#import "ui/base/cocoa/rtl_util.h"
 #import "chrome/browser/ui/cocoa/profiles/avatar_menu_bubble_controller.h"
 #import "chrome/browser/ui/cocoa/profiles/profile_chooser_controller.h"
 #include "components/signin/core/common/profile_management_switches.h"
@@ -159,7 +159,7 @@ bool ProfileUpdateObserver::HasAvatarError() {
 
   // The new avatar bubble does not have an arrow, and it should be anchored
   // to the edge of the avatar button.
-  int anchorX = cocoa_l10n_util::ShouldFlipWindowControlsInRTL()
+  int anchorX = cocoa_rtl_util::ShouldFlipWindowControlsInRTL()
                     ? NSMinX([anchor bounds]) + kMenuXOffsetAdjust
                     : NSMaxX([anchor bounds]) - kMenuXOffsetAdjust;
   NSPoint point = NSMakePoint(anchorX,